better inline schema naming for double byte characters

modules/openapi-generator/src/main/java/org/openapitools/codegen/InlineModelResolver.java

@@ -306,7 +306,8 @@ public class InlineModelResolver {
             if (schema.getAdditionalProperties() != null) {
                 if (schema.getAdditionalProperties() instanceof Schema) {
                     Schema inner = (Schema) schema.getAdditionalProperties();
-                    String schemaName = resolveModelName(schema.getTitle(), modelPrefix + this.inlineSchemaNameDefaults.get("mapItemSuffix"));
+                    String schemaName = resolveModelName
+                            (schema.getTitle(), modelPrefix + this.inlineSchemaNameDefaults.get("mapItemSuffix"));
                     // Recurse to create $refs for inner models
                     gatherInlineModels(inner, schemaName);
                     if (isModelNeeded(inner)) {
@@ -679,7 +680,7 @@ public class InlineModelResolver {
      * @return if provided the sanitized {@code title}, else the sanitized {@code key}
      */
     private String resolveModelName(String title, String modelName) {
-        if (title == null) {
+        if (title == null || "".equals(sanitizeName(title).replace("_", ""))) {
             if (modelName == null) {
                 return uniqueName("inline_object");
             }

modules/openapi-generator/src/test/java/org/openapitools/codegen/InlineModelResolverTest.java

@@ -411,6 +411,16 @@ public class InlineModelResolverTest {
                 requestBodyReference.getContent().get("application/json").getSchema().get$ref());
     }
 
+    @Test
+    public void resolveInlineRequestBodyWithTitleInChinese() {
+        OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_0/inline_model_resolver.yaml");
+        new InlineModelResolver().flatten(openAPI);
+
+        RequestBody requestBodyReference = openAPI.getPaths().get("/resolve_inline_request_body_with_title_in_chinese").getPost().getRequestBody();
+        assertEquals("#/components/schemas/resolveInlineRequestBodyWithRequired_request_1",
+                requestBodyReference.getContent().get("application/json").getSchema().get$ref());
+    }
+
     @Test
     public void nonModelRequestBody() {
         OpenAPI openAPI = TestUtils.parseSpec("src/test/resources/3_0/inline_model_resolver.yaml");

modules/openapi-generator/src/test/resources/3_0/inline_model_resolver.yaml

@@ -64,6 +64,21 @@ paths:
       responses:
         '200':
           description: OK
+  /resolve_inline_request_body_with_title_in_chinese:
+    post:
+      requestBody:
+        content:
+          application/json:
+            schema:
+              title: 服務條款和私隱政策
+              type: object
+              properties:
+                just_property:
+                  type: string
+      operationId: resolveInlineRequestBodyWithRequired
+      responses:
+        '200':
+          description: OK
   /non_model_request_body:
     post:
       requestBody: